For me, every bite by mosquito results in heavy itching and the blister, which size is dependent on how long the mosquito was sucking the blood, in worst cases even 1 cm in diameter. If I would stay naked outdoors the whole nights, the blisters would probably cover my whole body with painful red crust. It could be very dangerous for the whole body, I think.

But our ancestors have to stay naked the whole day and night outdoors. There are still tribes in Amazon and South Africa, that sleep naked in the open air. How to they deal with mosquito bites? It is possible for body to get used to bites and not react to the bites with blisters? Or the skin can get thicker so that to make it hard for mosquito to get through?

I don't know about "get used to," but I really don't get any reaction from mosquito bites. Maybe a bit of itching for a few minutes, nothing more. Possibly because I grew up in a highly mosquito-infested area, which would imply acclimatization is possible.
–
Kevin♦Jul 12 '13 at 2:01

3

Just because humanity has survived through something for thousands of years doesn't mean our ancestors had some sort of immunity we've lost. Good examples are polio and malaria (and malaria still kills hundreds of thousands per year).
–
Russell Steen♦Jul 17 '13 at 21:48

Strictly speaking, you want what an immunologist calls 'tolerance'. The itching and inflammation comes from our abundant immunity (that is, most of us have antibodies in our blood ready to react to whatever the mosquito leaves in the bite). My experience is that the first bite in the spring is the worst, and severity of the reaction decreases after that.
–
PepiFeb 26 at 1:40

Yes, increased exposure can reduce the ellergic reaction that results in the itching and swelling. The very first time we are bitten by a mosquito, nothing happens. That triggers the immune system in a way that subsequent bytes cause a allergic response.

There are roughly two levels of "immunity" to mosquitos that in most people can be brought on by high exposure. The first level will itch for a some minutes, but then after about 20 minutes or so the itch is gone and so is the redness and swelling. In fact, it's hard to remember where exactly the moquito bite was. I know because my body now responds this way.

From what I've read, the second level works the same way but symptoms are gone in about 2 minutes instead of 20 minutes. I can't comment on this from personal experience.

Mosquitos used to bother me and cause itching, redness, and swelling of a small area around the bite for days, like they do for most people. About 25 years ago I was doing a 2 night bike trip with a friend from Wellfleet on Cape Cod back to home in north-central Massachusetts. It was summer and quite warm and we didn't have tents, just a sleeping bag each and a platic sheet in case it rained (fortunately it didn't). The first night the mosquitos were really annoying. I sortof tried to cover myself with the plastic, but that got really hot and sweaty, and I still had to breath of course. Eventually I fell asleep anyway.

The next morning I got up and all was fine, then I remembered the mosquitos the night before and noticed to my great surprise that I couldn't find a single mosquito bite anywhere on my face, which was exposed all night. Ever since then, I've had the 20 minute reaction instead of the usual several day reaction.

However, while this makes the mosquito bites themselves more tolerable, it does nothing against the pathogens the mosquitos might carry. Around here we have West Nile and Easter Equine Encephalitis. Those can be pretty serious, but Malaria, Yellow Fever, and Dengue Fever effect many more people around the world. So don't go around thinking it's OK to be bitten by mosquitos just because your body has a tolerable reaction to the mosquito bite itself.